scholarly journals Biometeorological Conditions during the August 2015 Mega-Heat Wave and the Summer 2010 Mega-Heat Wave in Ukraine

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 99
Author(s):  
Olga Shevchenko ◽  
Sergiy Snizhko ◽  
Sergii Zapototskyi ◽  
Andreas Matzarakis

The human-biometeorological conditions in Ukraine during two mega-heat waves were analyzed. The evaluation is based on physiologically equivalent temperature (PET). The calculation of PET is performed utilizing the RayMan model. The results revealed these two mega-heat waves produced strenuous human-biometeorological conditions on the territory of Ukraine. During the summer 2010 mega-heat wave, strong and extreme heat stress prevailed at about midday at the stations where this atmospheric phenomenon was observed. The mega-heat wave of August 2015 was characterized by a lower heat load. The diurnal variation of PET values during the researched mega-HW was similar to that of the diurnal variation of air temperature with minimum values in the early morning and maximum values in the afternoon. On the territory where mega-heat waves were observed, the number of days during which heat stress occurred for 9 h amounted to 97.6% for the period from 31 July to 12 August 2010 and 77.1% for the mega-heat wave of August 2015.

2021 ◽  
Vol 54/55 (54/55) ◽  
pp. 43-54
Author(s):  
Olga Shevchenko ◽  
Sergiy Snizhko ◽  
Mariia Matviienko

The objective of this research is to assess the bioclimate of the city of Kharkiv in the summer season using the human thermal index of physiologically equivalent temperature (PET). The RayMan model has been used to obtain PET values. The results suggest that most days in Kharkiv during the summer are characterized by heat stress of various intensity 65.7% in June, 84.6% in July, 77.1% in August. The average frequency of comfortable weather is very low, varying from 12.6 to 25%. During heat waves, the frequency of days in Kharkiv with heat stress increases significantly, amounting to 96.3%. The results of the Kharkiv bioclimate assessment using PET may be used to create measures for heat adaptation and develop infrastructure for recreation and tourism in the city during hot periods.


2014 ◽  
Vol 11 (4) ◽  
pp. 5969-5995
Author(s):  
C. C. van Heerwaarden ◽  
A. J. Teuling

Abstract. This study investigates the difference in land–atmosphere interactions between grassland and forest during typical heat wave conditions in order to understand the controversial results of Teuling et al. (2010) (T10, hereafter), who have found the systematic occurrence of higher sensible heat fluxes over forest than over grassland during heat wave conditions. With a simple, but accurate coupled land–atmosphere model, we are able to reproduce the findings of T10 for both normal summer and heat wave conditions, and to carefully explore the sensitivity of the coupled land–atmosphere system to changes in incoming radiation and early-morning temperature. Our results emphasize the importance of fast processes during the onset of heat waves, since we are able to explain the results of T10 without having to take into account changes in soil moisture. In order to disentangle the contribution of differences in several static and dynamic properties between forest and grassland, we have performed an experiment in which new land use types are created that are equal to grassland, but with one of its properties replaced by that of forest. From these, we conclude that the closure of stomata in the presence of dry air is by far the most important process in creating the different behavior of grassland and forest during the onset of a heat wave. However, we conclude that for a full explanation of the results of T10 also the other properties (albedo, roughness and the ratio of minimum stomatal resistance to leaf-area index) play an important, but indirect role; their influences mainly consist of strengthening the feedback that leads to the closure of the stomata by providing more energy that can be converted into sensible heat. The model experiment also confirms that, in line with the larger sensible heat flux, higher atmospheric temperatures occur over forest.


2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A73.2-A73
Author(s):  
Matthias Otto ◽  
Tord Kjellstrom ◽  
Bruno Lemke

Exposure to extreme heat negatively affects occupational health. Heat stress indices like Wet Bulb Globe Temperature (WBGT) combine temperature and humidity and allow quantifying the climatic impact on human physiology and clinical health. Multi-day periods of high heat stress (aka. heat waves) affect occupational health and productivity independently from the absolute temperature levels; e.g. well-documented heat-waves in Europe caused disruption, hospitalisations and deaths (2003 French heat wave: more than 1000 extra deaths, 15–65 years, mainly men) even though the temperatures were within the normal range of hotter countries.Climate change is likely to increase frequency and severity of periods of high heat stress. However, current global grid-cell based climate models are not designed to predict heat waves, neither in terms of severity or frequency.By analysing 37 years of historic daily heat index data from almost 5000 global weather stations and comparing them to widely used grid-cell based climate model outputs over the same period, our research explores methods to assess the frequency and intensity of heat waves as well as the associated occupational health effects at any location around the world in the future.Weather station temperature extreme values (WBGT) for the 3 hottest days in 30 years exceed the mean WBGT of the hottest month calculated from climate models in the same grid-cell by about 2 degrees in the tropics but by 10 degrees at higher latitudes in temperate climate regions.Our model based on the relationship between actual recorded periods of elevated heat-stress and grid-cell based climate projections, in combination with population and employment projections, can quantify national and regional productivity loss and health effects with greater certainty than is currently the case.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242279
Author(s):  
Paul J. Jacobs ◽  
M. K. Oosthuizen ◽  
C. Mitchell ◽  
Jonathan D. Blount ◽  
Nigel C. Bennett

Heat waves are known for their disastrous mass die-off effects due to dehydration and cell damage, but little is known about the non-lethal consequences of surviving severe heat exposure. Severe heat exposure can cause oxidative stress which can have negative consequences on animal cognition, reproduction and life expectancy. We investigated the current oxidative stress experienced by a mesic mouse species, the four striped field mouse, Rhabdomys dilectus through a heat wave simulation with ad lib water and a more severe temperature exposure with minimal water. Wild four striped field mice were caught between 2017 and 2019. We predicted that wild four striped field mice in the heat wave simulation would show less susceptibility to oxidative stress as compared to a more severe heat stress which is likely to occur in the future. Oxidative stress was determined in the liver, kidney and brain using malondialdehyde (MDA) and protein carbonyl (PC) as markers for oxidative damage, and superoxide dismutase (SOD) and total antioxidant capacity (TAC) as markers of antioxidant defense. Incubator heat stress was brought about by increasing the body temperatures of animals to 39–40.8°C for 6 hours. A heat wave (one hot day, followed by a 3-day heatwave) was simulated by using temperature cycle that wild four striped field mice would experience in their local habitat (determined through weather station data using temperature and humidity), with maximal ambient temperature of 39°C. The liver and kidney demonstrated no changes in the simulated heat wave, but the liver had significantly higher SOD activity and the kidney had significantly higher lipid peroxidation in the incubator experiment. Dehydration significantly contributed to the increase of these markers, as is evident from the decrease in body mass after the experiment. The brain only showed significantly higher lipid peroxidation following the simulated heat wave with no significant changes following the incubator experiment. The significant increase in lipid peroxidation was not correlated to body mass after the experiment. The magnitude and duration of heat stress, in conjunction with dehydration, played a critical role in the oxidative stress experienced by each tissue, with the results demonstrating the importance of measuring multiple tissues to determine the physiological state of an animal. Current heat waves in this species have the potential of causing oxidative stress in the brain with future heat waves to possibly stress the kidney and liver depending on the hydration state of animals.


2021 ◽  
Author(s):  
Joakim Kjellsson ◽  
Nils Niebaum ◽  
Robin Pilch Kedzierski

<p>We investigate how European heat waves and their associated heat stress on humans have changed over the 20th century. We find that the heat stress has increased, even in regions where heat waves have not become warmer. As heat stress increases over wide areas of Europe there is also an increase in the total population affected by the heat stress. </p><p>Heat waves pose a serious health risk to humans by reducing our ability to shed heat. We have studied the occurrence and intensity of heat waves as well as a heat stress index based on simplified wet-bulb globe temperature using data from ERA-20C reanalysis 1900-2010. Over the 110 years of data we find an overall warming of the air temperatures and dew point. The 98th percentile of both air temperature has increased by more than 1.5°C over large areas of Europe. </p><p>We find an overall increase in heat wave days per year as well as an increase of air temperature during heat waves over most of Europe. As such, many densely populated areas exhibit increased heat stress during heat waves. For example, the mean heat stress during heat wave days over Paris has increased by one level, from “alert” in 1900-1930 to “caution” in 1980-2010. The fraction of the population exposed to heat waves has increased by 10%/century in central Europe and 25%/century over the Mediterranean. </p><p>We find more heat waves during 1920 - 1950, which may be related to the positive phase of the Atlantic Multidecadal Variation (AMV). This suggests that the heat stress during European heat waves may also be influenced by internal climate variability, and large-ensemble model simulations may be used to disentangle the effects of natural variability and anthropogenic forcing.</p>


2021 ◽  
Author(s):  
Biljana Basarin ◽  
Tin Lukić ◽  
Tanja Micić Ponjiger

<p>A detailed analysis of extreme heatwave events in Serbia from the biometeorological point of view is presented in this study.  For this purpose, the newly developed Heat Wave Magnitude Index daily (HWMId), was used on Physiologically equivalent temperature (PET) for Serbia. A series of daily maximum air temperature, relative humidity, the wind was used to calculate PET for the investigated period 1979–2019. HWMId is defined as the maximum magnitude of the heatwaves in a year. Here, the heatwave is characterized as 3 consecutive days with maximum PET above the daily threshold for the reference period 1981–2010. The analysis revealed that during the investigated period the most intensive heat waves occurred in 2007, 2012 and 2015. HWMId values for 2007 were in the range of 8 to 23 indicating extreme heat stress, while for the other two events the values were not as high. Hourly temperatures revealed that the PET values during the day were as high as 55°C. Thus, the mitigation and adaptation to extreme temperature events are of vital importance for humans and their everyday activities. Future investigation should be oriented towards a way to deal with the oppressive heat. Additionally, more research is needed in order to explain and predict these catastrophic events. The main focus of future activities will be on determining the physical causes which lead to the occurrence of extreme heatwaves.</p><p>Keywords: Heat Wave Magnitude Index daily, Physiologically equivalent temperature, Serbia, heat waves</p><p>Acknowledgment: This research is supported by <strong>EXtremeClimTwin</strong> project funded from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 952384</p>


Author(s):  
A. Walzer ◽  
T. Steiner ◽  
B. Spangl ◽  
E. Koschier

AbstractClimate change models predict that the frequency, intensity and duration of heat waves will increase in the next decades. Heat waves can have profound impact on the reproduction of biocontrol agents ranging from postponing oviposition to manipulating offspring quantity via egg number and quality via egg size. Such species-specific responses of biocontrol agents to heat stress may also affect their success in controlling the target pest. Here, we evaluated the predation and reproductive performance of the two spider mite predators Phytoseiulus persimilis and Neoseiulus womersleyi exposed to simulated mild, moderate and extreme heat wave conditions over three days. Irrespective of heat wave conditions, all N. womersleyi females survived, whereas 12% of the P. persimilis females died. Both species responded to heat stress via plastic modifications resulting in increased predation rates and smaller egg sizes. Significantly more P. persimilis females postponed oviposition during the experimental phase than N. womersleyi. The deposited egg number of Phytoseiulus persimilis was not affected by heat wave conditions. On the contrary, the reproductive output of N. womersleyi was a function of temperature, i.e., the higher the temperature, the higher the number of deposited eggs. These findings indicate that P. persimilis is more heat sensitive in relation to reproduction than N. womersleyi. However, further investigations of heat wave effects on other fitness-related traits and their consequences at population level are needed to find out whether N. womersleyi is an alternative or supplement to P. persimilis as spider mite control agent under heat waves.


2021 ◽  
Vol 11 (1) ◽  
pp. 929-936
Author(s):  
Iwona Szer ◽  
Jacek Szer

Abstract The aim of the article was to present the influence of the external environment on people working on scaffolding. For this purpose, the heat load of a man was determined using the universal thermal climate index. The research was carried out on 40 facade scaffolds located in four voivodeships in Poland: Lower Silesia, Lublin, Lodzkie, and Masovian. The conducted analysis showed that employees may experience strong or very strong heat stress, and also extreme heat stress in isolated cases. The highest probability at 0.30 level occurs on scaffolds located in the Lodzkie voivodeship. Environmental conditions are therefore unfavourable for people working outside. This can lead to reduced concentration, longer reaction time, and greater fatigue, contributing to an increase in situations that could lead to accidents. Hazard identification allows to take safety measures that improve the comfort of work on scaffolding.


2019 ◽  
Author(s):  
Milica M. Pecelj ◽  
Milica Z. Lukić ◽  
Dejan J. Filipović ◽  
Branko M. Protić

Abstract. The objective of this paper is the assessment of bioclimatic conditions in Sebia. A special emphasis has been given to the heat budget bioclimatic Universal Thermal Climate Index (UTCI) whose purpose is to evaluate degree of thermal stress that human body is exposed to during the last twenty years. In addition, the thresholds of daily maximum temperatures are analysed in order to identify increase and frequency of heat waves in Serbia. For this research, daily and hourly (07 h and 14 h) meteorological data from 3 weather station (Mt. Zlatibor, Novi Sad, Niš) are collected for the period 1998–2017. The results show that the most frequent UTCI heat stress categories are strong heat stress and very strong heat stress. The most extreme heat waves events are occurred in 2007, 2012, 2015 and 2017. Moreover, there were three Heat wave events (HWE) in Niš occurred in July, 2007 lasting 3, 10 and 4 days in row. Heat wave events (HWE) In July 2007 (10 days) and July 2012 (9 days) in Niš are occurrences with maximum number of days in row recorded.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 150-150
Author(s):  
Stephanie L Sammes ◽  
Angela M Lees ◽  
Judy A Cawdell-Smith ◽  
John B Gaughan

Abstract Body temperature (BT) is a reliable method for evaluating the thermal status of cattle. The objective of this study was to evaluate the regulation of BT in B. indicus and B. taurus steers during a heat wave event. Thirty-five steers (466.30±10.2kg) of mixed genotypes (B. taurus, n = 18; B. indicus, n = 17) were used in a larger 100-d study. Cattle were housed in six un-shaded pens at a commercial feedlot. Body temperature data for this were obtained at 1 h intervals over a 3-d heat wave event using in situ abdominal data loggers. Data were analysed using a repeated measures model, using residual maximum likelihood estimation. The model included genotype (B. taurus; B. indicus) and animal ID as random effects and hour as a fixed effect. Mean maximum BT occurred at 1500 h for B. taurus (40.52±0.03ºC) and 0400 h for B. indicus (40.48±0.31ºC). The BT of B. indicus decreased between 0400 h and 0700 h, and then increased to 1100 h (+0.10±0.01ºC/h), before decreasing again. The BT of B. taurus decreased between 0500 h and 0600 h, and then slowly increased (+0.04±0.01ºC/h) to 1500 h. Mean minimum BT occurred at 2100 h for B. taurus (40.12±0.11ºC) and 0700 h for B. indicus (40.00±0.22ºC). B. taurus maintained lower BT (40.21±0.05ºC) between 1900 h and 2200 h compared to B. indicus (40.27±0.05ºC) which may be due to disrupted heat loss mechanisms during the day, highlighting the importance of night time cooling. In response to increasing heat load, BT in B. taurus had slower increases but retained heat for longer, whilst B. indicus BT responded by a series of rapid increases and decreases. Developing an understanding of the differences in BT regulation in B. indicus and B. taurus will allow for more effective heat load management strategies during heat waves to be established.


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